Transmission system



A ril 11, 1944. G. s. LlGHT TRANSMISSION SYSTEM a Sheets-Sheet 1 Filed Jan. 29, 1942 r0 no.2

.EDUmIU nEOU QZOUNW INVENTOR ATTO RN EY April 11, 1944.

G. G. LIGHT TRANSMISSION SYSTEM Filed Jan. 29, 1942 3 Sheets Sheet 2 II- II- INVENTOR -c. G. Ll GHT m 'TO FIG.3'

-To FlG.l ATTORNEY -llll INVENTOR ATTORNEY 3 Sheets-Sheet 3 G. G. LlG'HT TRANSMISSION SYSTEM Fi led Jan. 29, 1942 April 11, 1944.

Fllll m wE Patented Apr. 11, 1944 UNITED STATES PATENT OFFICE TRANSMISSION SYSTEM George G. Light, Kew Gardens, N. Y., assignorto The Western Union Telegraph Company, New York, N. Y., a corporation of New York Application January 29, 1942, Serial No. 428,647

17 Claims.

This invention relates to telegraph transmission systems, and more particularlyto multiple selective transmission systems wherein a single message is transmitted concurrently to two. or more selected lines or stations. 7

The principal object of the invention is to provide a System in which messages may be broadcast to different groups of stations selected at the time of transmission, and in which the selected lines over which a particular message is broadcast and also the group selection equipment are automatically released and restored to normal at the end of each broadcast message so that the lines are immediately available for the transmission of other messages.

Another object of the invention is to provide improved restoring means for the group selection means in a broadcast or multiple circuit transmission system.

In accordance with the invention as embodied in a telegraph exchange system having a plurality of lines to outlying branch ofiices or stations terminating at a main switching ofiice or exchange, means'are provided whereby any two or more of the lines may be seized for simultaneous transmission of a message to any two ormore selected branch omcesor stations. Selective manually operable means, such as a series of key switches, is provided forseizing the desired lines as soon as they become idle, and after all of the lines selected have become idle, a stored message at the exchange is transmitted simultaneously to all of the branch ofiices or stations on the selected lines. lines are released for other calls and the manually operable control equipment restored to normal so as to avoid any delay in transmission of subsequent messages for any of the stations involved in the broadcast transmission. Preferably, the release of the lines and restoration of the control equipment. is efiected in response to code combinations appended to; the message and forming anend-of-message signal, "but, if desired, other means may be provided whereby these functions are effected (after the. message is transmitted) fromthe operator's position associated with the storage and repeating equipment.

For a better understanding of the invention, reference may be made to the following detailed description of a preferred embodiment of the invention shown in the accompanying drawings, wherein:

Figs. 1, 2 and 3, taken'together, illustrate'diagrammatically a telegraph exchange system according to the invention- The figures of the At the end of the message the selected drawings illustrate the repeating equipment and the selective control'apparatusat a main switching station or exchange in which messages stored in the form of perforated tape may be transmitted to selective stations through selective switching apparatus of the manual switchboard type. Fig. 3 also illustrates the outgoing line circuits extendingto,three remotebranch ofiices or stations.

Referring to Fig.v 1 of the drawings, tape transmitters TTl and 'IT Z represent two sources of signals associated with cord circuit control equipment whereby messages stored in thetape at the tapetransmitters may be repeated over a line selected at the switchboard represented by the jacks H to 16, shown inlf'ig. 2. vThe jacks II and I4 represent the switching terminals ofone branch office lineat two positions of the switchboard, whereas the jacks l2 and I5 represent similar terminals of a second line. The jacks I3 and it are the multisend jacks at each position employed for transmitting a single message concurrently to any two or more selected lines as determined by the control. equipment shown in the right hand half of Fig. 2 and in Fig. 3. It will be understood that, while only two line jacks at each of two positions of the switchboard are shown, similar jacks would beprovided for additional lines and, if additional positions were required, the switchboard jacks at such'additional positions would be m11ltipled to those shown in the same manner as the two positions illustrated,

As indicated in Fig. 1, two reperforators RI and R2 are associated with the respective tape transmitters TTI and TT2 in order to record messages received over the line'circuits terminating in said 'repe'rforators from distant stations (not shown).

Obviously, tape for the tape transmitters could be prepared by local keyboard, perforators, or

other equivalent means of storing and repeating messages could be substituted for the tape perforating and transmitting equipment illustrated. The controlapparatus and circuits in the cord circuit? associated with. thetape transmitter IT! and terminating in theswitchboard plug [8 are illustrated in some detail, the circuits and control equipmentof the second cord circuit being similar to that illustrated in connection with the first cord circuit. The arrangement illustrated in Figs. 1 and, 2 for storing a message received from a distant station, repeating the same over a selected line circuit as soon as the same becomes idle and releasing the line circuit at the end of the message is generallysimilar to that shown and described in the prior patent to Blanchard et a1. 2,193,811, dated March 19, 1940, or the upon the insertion of a plug l8 in the jack H or- 2, or the insertion of a plug Is at the second position in the jack H or l5. that the repeater including the transmitter TTI- may be plugged into the switchboard whether the selected line is busy or idle, and the operation of the tape transmitter'will be initiated automatically when the line becomes idle under thecontrol of the circuit allotter CA. The end-ofmessage signal, which for the purposes of the present description will be assumed to consist of a double carriage return signal, is employed for the purpose of stopping the. tape transmitter, lighting the'disconnect lamp 2| and releasing the line-for transmission of another message which may be plugged into said line at another posi tion of the switchboard.

The tape transmitter TTI, as shown for the purpose of explaining the invention, is of the type employedv in the above-mentioned patents and comprises. marking and. spacing bus bars selectively engaged by five selectively operable contacts. which are set in accordance with the perforations in the tape, together with a stepping magnet 22- arranged to stepthe tape through the transmitter and project and retract. the tape feeler's'controlli'ng the adjustable. contacts. The contacts of the tape transmitter are connected to code reading relays 25, 26, 21, 28. and 29, which become energized whenever an associated transmitter contact, engages the spacing bus bar and thus respond to each code combination transmitted. Theusual distributor 30. is. employed in connection, with the tape. transmitter; asweliknown to those skilled in the art; The distributor 30' is provided with a series of transmitting contacts 3| which are closed in proper sequence during the operating cycle of. the distributor to generate code impulses through the inner armatures .of the relays 25 to 29, inclusive, which are transmitted through the inner-right hand armature and front contact of relay 32 and the conductor 33 to the tip contact of the plug I8. The distributor is shown as provided with a clutch magnet which, when energized, releases a cam shaft for operation of the distributor contacts, but any suitable form of distributor may be employed. The distributor is further provided with two auxiliary pairs of contacts 34 and 35,v contacts 34 being closed near the end of transmission of each code combination whereas the contacts 35 are closed after the fifth code impulse to energize the stepping magnet 22 of the tape transmitter.

The code reading relays 25 to 29, inclusive, are further provided with. contacts forming a baflle circuit through the outer armatures of said relays which is closed when the "carriage return code combination (No. 4 only marking) is set up in. the tape transmitter. The control relays an to 44, inclusive, cooperate with the baffle circuit through. the contacts of the code reading relays 25 to 29 to close a circuit. to stop the transmitter upon the receipt of twosuccessive carriage return signals. The stopping of the tape transmitter and releaseof the line upon the reception of the end-of-message signal is accomplished in It will be understood substantially the same manner as set forth in the above-mentioned patents, but in accordance with the present invention the end-of-message signal is also utilized to restore the selective equipment associated with the multiple selective transmission apparatus shown in Fig. 3 in a manner that will be explained below. The holding relay 37 remains locked up through the conductor 38 and the sleeve contacts of the jack I3- and plug I 8 until the plug is removed from the jack. The holding relay 31 further closes through its right .hand outer armature and front contact the circuit of the disconnect lamp 2| which remains lighted until the plug is withdrawn from the jack.

As: shown, the tape lever contacts 45, which are opened when the tape between the reperforator El and the tape transmitter TTI becomes taut.

are disposed in the circuit of the clutch magnet of the distributor 30 to prevent operation of the distributor upon the occurrence of tight tape.

.Since the operation of the system in repeating a stored message through the switchboard to any one of the line circuits is the same as in the systems described in the above-mentioned patents, the following description will be confined to the functions of the system involved in transmitting a message simultaneously to any two or more of the line circuits to stations A, B, etc. in Fig. 3. Each of the line circuits to the individual branch stations is provided with a line seizing relay such as relay 5|, Fi 2, for station A, or relay 52 for station B, said relays being energized'when the line is selected at the switchboard and maintained. energized until transmission of the message is completed. Since one or more of the lines selected for broadcast transmission may be in use at the time the multiple selection is initiated, actual transmission is delayed until the lin seizing relays 55, 52 of the selected lines become'deenerized to indicate that transmission of previous messages has been completed. In order to transmit a message stored in the storage and repeating equipment RI, TTI of Fig. I simultaneously to stations A and B, the operator inserts the plug l8 in the multisend jack 3 of Fig. 2, closes the cord circuit selector key switch 55 corresponding to the cord circuit terminating in the plug I8 and actuates the line selecting key switches 6| and 62, Fig. 3, and the master start key 65. It is to be noted that only one multisend jack I3 or IE is provided for each cord circuit or operators position, and the cord circuit selection key switches 55, 56 and 51 are interlocked so that only one switch may be operated at a time, the operated switch remaining closed until multiple transmission from another cord circuit is desired. Thus, only one cord circuit will be operative to transmit to a selected group of lines or stations, although more than one cord circuit plug may be inserted at the same time in the series of multisend jacks such as |3, Hi.

When the plug I8 is inserted in the multisend jack l3, as described above, a circuit is closed from ground through the sleeve contacts of the jack l3 and plug 8, the conductor 38, the right hand inner armature and back contact of the holding relay 31', the conductor 39, the ring contacts of the plug is and jack I3, the conductor 53 and the left hand outer armature and back contact of relay 18 for lighting the "request lamp 66 to indicate at a point adjacent the multisend control equipment that the equipment is desired by one of the operators. Upon the momentary actuation of the keys 6| .and 62, which are of the non-locking tyne. the

associated selector relaysll. and 12 become operated and are locked up through their right hand inner armatures and front contacts and the supervisory lamps 14 and 15 to ground at the armature of relay 11.

On the actuation of the non-locking start key 65 after the circuit selection keys 6! and 62 have been actuated as described above, a circuit is closed from ground through the left hand armature and back contact of relay Tl, supervisory lamp 19, the contacts of the key 55 and the winding of relay 18 to battery, whereupon relay 18 becomes energizedand locks up through its left hand inner armature and front contact independently of the contacts of the key 55. The energization of relay I8 closes a circuit through its inner right hand armature and front contact for operating slow-release relay 9?. If the selected circuits to stations A and B are idle at this moment, the operation of the numbering machines 8i and 82 is initiated, after which the transmitter TT! is started to transmit the message simultaneously to stations A and B. Operation of the transmitting equipment/is initiated by start relay 85 through a circuit extending from battery through the resistance 86, the left hand middle armature and front contact of relay 18, the winding of relay 85, the conductor 87, the contacts of the locking key 55, the lower make contacts of the jack l3, conductor 88, winding of the start relay 32 of the cord circuit, the left hand armature and back contact of relay 3! and the contacts of the circuit allotter CA to ground.

However, if either of the selected circuits is in use, for example, that to station A, the winding of relay 85 is short-circuited through the right hand inner armature and back contact of said relay, the second left hand armature and front contact of relay H, conductorBS, and the right hand outer armature and front contact of the line-seizing relay 5|, which, as stated above, remains energized until the circuit becomes idle. Similarly, the circuit through the right hand outer armature and front contact of relay 52 maintains the start relay 85 deenergized as long as the line to the second station is in use. Furthermore, when transmission of a previous message is completed over either of said line circuits, the

operating circuit for the relay 5| or 52, including conductor 90 or 9|, is opened at the third left hand armature and back contact of relay H or .12 to prevent the subsequent seizure of said line at the switchboard until the broadcast transmission has been effected.

The lines extending to the branch stations A, 3, etc., Fig. 3, terminate at the main switching office or exchange on the marking contacts of the. line relays IOI, IE2 and H33, the windings of which .are connected in a series circuit extend .ing from negative battery through the resistance I84 and conductor I05 to the tip contacts of the multisend jacks l3, I6, etc. The transmitting circuit from the tape transmitter T'I'i may be traced through the inner armatures and back contacts of the code reading relays to 38 set in accordance with the successive code combinations in the tape, the right hand inner armatrue and front contact of relay 32, the conductor 33 to the tip contact of jack l3. After the operation of the master start key 65 and until broadcast transmission is commen'ced'over each of the selected line circuits, the conductor N is grounded at the left hand armature and back contact of the start relay 85 to prevent the opening of any of the line circuits by the'line' relays |0I,l02,etc.

When the selected line circuits become idle, relay becomes energized over the above-described circuit including the conductor 81 and the operated cord circuit selector key switch 55,

55, etc., whereupon circuit is closed from ground through the second right hand armature and front contact of relay 85 and the winding of relay 95, whereupon relay becomes energized. The energization of relay 95 closes circuits through the right hand outer armatures and front contacts of the selected circuit relays H and I2 to energize the start circuits I01 and M8 to the numbering machines BI and 82 associated with the selected lines. These numbering machines, which may be of the type described'in the above-mentioned patent to Blanchard et al. No. 2,193,811 or in the patent to Dirkes et al. No. 2,193,809, are operative to transmit a number or other desired service code signal group over the associated line circuit preceding each message; At the end of the number or code signal group, contacts HI and I l2 of each machine are closed momentarily, as described in the above mentioned patents, whereupon a circuit is closed through the winding of relay 95, the right hand outer armature and front contact of relay 85, the left hand inner armature and front contact of relay H, contacts I I l, the left hand inner armature and front contact of relay 12, contacts H 2,

.and the left hand inner armatures and back'contacts of the unoperated relays of unselected circuits corresponding to relay 13, to ground.

The energization of relay 95 is, therefore, effected immediately upon the completion of the transmission of the numbers'o-r service code signal groups over the selected lines, and said relay becomes locked up through its left hand'inner armature and front contact to ground at the right hand outer armature and front contact of relay T8. The energization of relayQG opens thecircuit of slow-release relay 9'! and," after a short interval, the latter relay becomes deenergized and closes a circuit that may be traced from ground through the right hand armature and front contact of relay 95, the armature and back contact of relay ill, the conductor M5, the pper make contacts of the'jack l3, conductor M5, the right hand outer armature and front contact of the seize relay 32 of the cord circuit, the tape lever contacts 45, the right'hand armature and back contact of relay 43 and the winding of the clutch magnet of the distributor 30 to initiate transmission of the message stored in the tape at the transmitter TTI. The line relays HM and I 52 which are connected to the tip circuit of the plug I8 and jack l3, as described above, respond to the successive code combinations sent from the transmitter TT! and thus the message stored in the tape is transmitted simultaneously to stations A and B, Fig. 3. The operation of the line relay I03 does not aifect the electrical conditions of the line circuit extending to 'the third station, since the transmitting contacts of said relay are shortcircuited through the left hand outer armature and back contact of the deenergized selection relay 13 individual to the unselected station.

At the end of the message, the code reading relays 25 to 29, inclusive, and the associated control relays 4b to 44, inclusive, respond to the end-of-inessage signal to stop the transmitter, release the line circuits and restore the multiple circuit selection equipment of Fig. 3. When'the carriage return code combination, consisting of No. 4 marking, is set up in thetape transmitter TTI, relays 2-5, 25, 27 and 29 become energized, and relay 28 remains deenergized. Thereupon a circuit is closed from battery through the armature and back contact of relay 42, the winding of relay 40, the left-hand armature and back contact of relay 4|, the right hand outer armature and back contact of relay 28, the right hand outer armatures and front contacts of relays 29, 21, 2B and 25, the left hand outer armature and back contact of relay 44 and the intermittently operated contacts 34 of the distributor 38 to ground, whereupon relay 4!] becomes energized. At the end of the transmission of the carriage return code combination, the contacts 34 of the distributor open, and relay 48 locks up through its inner armature and front contact and the winding of relay 4| to ground at the left hand armature and front contact of relay 32. If the next code combination is not a carriage return, reset relay 42 becomes energized in an obvious manner and releases the counting relays 4D and 4|. If, however, the next code combination is also a carriage return, a circuit is closed from battery through the winding of relay 43, the armature and front contact of relay 4! and the abovedescribed bafile circuit through the contacts of relays to 29, whereupon relay 43 becomes energized and locks up in series withrelay 44 at the end of the code combination when the contacts 34 of the distributor open. The operation of relay 44 opens the locking circuit of relay 32, thus deenergizing said relay, which in turn releases relays 40, 4!, 43 and or. When the circuit of relay 32 is opened, as described above, relay 85 in series relation with said relay becomes deenergized, whereupon a circuit is closed through the right hand middle armature and back contact of said relay and the lefthand middle armature and front contact of relay 96 for operating the release relay H. The energ-ization of relay 7'! open the locking circuits of relays H and I2, whereupon said relays become deenergized and the supervisory lamps l4 and 75 are. extinguished. The deenergization of relay 85 also opens at its right hand armature and front contact the circuit of relay 95, whereupon said relay is restored to normal. The energization of relay 71, as described, opens at its left hand armature and back contact the locking circuit of relay l8, whereupon said relay becomes deenergized and opens at its right hand outer armature and front contact the lockin circuit of relay 9E. The supervisory lamp 79 in series with the relay I8 is extinguished. In this manner the operated equipment associated with the multiple selection circuit control of Fig. 3 is restored to normal in response to the end-of-message signal perforated in the tape at the trans mitter TTI. It will be noted that a release key 12! is provided for operating the release relay 11 in the event that a mistake is made in initialli operating one of the selection keys BI, 62 or 53, since the operation of relay T! will release the associated selection relays H, '12 and T3 and permit a mistake to be corrected and the proper keys operated.

While the release of the manually operable selection equipment of Fig. 3 is described as being effected automatically in response to the end-of-message signal appended to each message being transmitted, obviously the equipment could be restored after the message had been transmitted when the plug, I8, is removed from a jack or by the operation of a switch associated with the cord circuit arranged to release relay when the message has been transmitted to the selected branch stations.

Various other modifications in the specific circuit diagram shown and described above, and in the type of transmitting, repeating and control elements employed couldbe made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A multiple selective telegraph transmission system comprising a main switching offlce or exchange, a plurality of branch offices or stations, lines connecting said branch offices or stations to said main switching ofiice, message repeating equipment at said main switching offlce, selective switching means for connecting said repeating equipment to selected lines over which messages are to be transmitted, operable means at said main switching ofiice for selecting a plurality of lines over which a single message is to be transmitted concurrently from said repeating equipment, means to initiate the operation of said repeating equipment when all of the lines of a selected group become idle and means to restore to normal the said means for selecting a plurality of lines over which a single message is to be transmitted concurrently at the end of the message.

2. A multiple selective telegraph transmission system comprising a main switching ofiice or exchange, a plurality of branch offices or stations, lines connecting said branch ofiices or stations to said main switching office, message transmitting equipment at said main switching oflic'e, selective switching means for connecting said transmitting equipment to selected lines over which messages are to be transmitted, other selective means for designating two or more of said lines over which a single message is to be transmitted simultaneously and for connecting said plurality of lines at the same time to said transmitting equipment and means responsive to an end-of-mes'sage signal appended to said single message for releasing said plurality of lines at the end of the message.

3. A multiple selective telegraph transmission system comprising a main switching office or exchange, a plurality of branch offices or stations, lines connecting said branch offi'ces or stations to said main switching office, message transmitting equipment at said main switching oflic'e, selective switching means for connecting said transmitting equipment to selected lines over which messages are to be transmitted, other selective means for designating two or more of said lines over which a single message is to be transmitted simultaneously and for connecting said plurality of lines at the same time to said transmitting equipment, means for stopping said message transmitting equipment at the end of each message and means associated with said last-mentioned means for restoring said other selective means to normal in readiness for subsequent broadcast transmission.

4. A multiple selective telegraph transmission system comprising a main switching ofiice or exchange, a, plurality of branch offices or stations, lines connecting said branch oifices or stations to said main switching office, message transmitting equipment at said main switching office, selective switching means for connecting said transmitting equipment to selected lines over which 1 messages are to be transmitted, other selective means for designating two or more of said lines over which a single message is to be,

transmitted simultaneously and for connecting said plurality of lines at the same time to said:

transmitting equipment, said last-mentioned means including a series of selecting relays, one for each line, and means for actuating the same when multiple transmission to a plurality of lines is desired, means to initiate transmission of a message to all of the selected lines and means operative at the end of the message to release said lines and restore said selecting relays to normal.

5. -A multiple selective telegraph transmission systemcomprising a main switching ofice or exchange, a plurality of branch ofiices or stations,

lines connecting said branch offices or stations to said main switching oiiice, message transmitting equipment at said main switching ofiice, selective.

switching means for connecting said transmitting equipment to selected lines over which messages are to be transmitted, other selective means for designating two or more of said lines over which a single message is to be transmitted simultaneously and for connecting said plurality of lines at the same time to said transmitting equipment, said last-mentioned means including a series of selecting relays, one for each line, and means for actuating the same when multiple transmission to a plurality of lines is desired, means to seize each of the desired lines as soon as idle, means to initiate transmission to all the desired lines after all have become idle and means responsive to an end-of-message signal appended to the message for releasing the selected lines and restoring said selecting relays to normal.

6. A multiple selective telegraph transmission system comprising a main switching office or exchange, a plurality of branch omces or stations, lines connecting said branch ofiices or stations to said main switching oflice, message transmitting equipment at said main switching omce, selective switching means for connecting said transmitting equipment to selected lines over which messages are to be transmitted, other selective means for designating two or more of said lines over which a single message is to be transmitted simultaneously and for connecting said plurality of lines at the same time to said transmitting equipment, said last-mentioned means including a series of selecting relays, one for each line, and means for actuating the same when multiple transmission to a plurality of lines is desired, means to seize each of the desired lines as soon as idle, means to transmit a supervisory code signal group over at least one of t e selected lines over which broadcast transmission is desired, means to initiate transmission of the broadcast message only after all of the desired lines have become idle and the supervisory code signal group has been transmitted and means including a control circuit closed at the end of the message for restoring said selecting relays to normal.

7. A multiple selective transmission system wherein concurrent transmission of messages over any two or more of a group of lines is effected and each message is terminated by an end-ofmessage signal, resettable elements, means including said resettable elements for selecting the desired ones of said lines over which transmission is to be effected simultaneously and means responsive to the end-of-message signal for resetting said elements to normal after transmiss on of the message.

iii-SA multiple selective, transmission system whereinboncurrent transmission of telegraph messagesover any two or more of a group of l nes is effected and each message is terminated by an end-oi-message signal, busy guard means,

. means including; said busy guard means to delay transmission oi the broadcast message until anor the selected lines become idle and means responsive to the end-of-message signal to restore the systemic normal for transmission of subsequent messages. 7 J

--9.- A selective telegraph transmision sytem for-ending messages over selected lines comprising a, transmitter, a manual switchboard including a connecting'plug iorextending the circult of said transmitter, and jacks forming terminals or said ;lines, said switchboard also conlines, means associated withsaid multisend jack ror seizing desired ones of said lines as'theybecome iQle and remote-control means for releasing the selected lines at the end of the mesa'ge.

1 10. A selective telegraph transmission system 1 ior sending messages over selectedlines comprising a transmitter, a manual switchboard includinga connecting, plug for extending the circuit u]; sa d transmitter, and jacks forming terminals or said lines, said switchboard also containing a multisend jack, means operative on the insertion of said connecting jack in said multisend J for sending messages simultaneously over any two or more selected lines of a group comprising a series of selective key switches, one for each oi the lines of ,said group, selective relays controlled by said key switches, a common locking circuit for aid relays efiective'to maintain the operated relays energized when the key switches are restored and means for interrupting said locking circuit at the end of a message to reset the selective equipment to normal.

12. A selective telegraph transmission system for sending messages simultaneously over any two or more selected lines of a group comprising a series of circuit controlling elements, one for each of said lines, means for actuating selected ones of said elements corresponding to the lines to which concurrent transmission is to be efiected, means including the contacts of the switching elements which have been actuated for delaying transmission until all of the selected lines are idle and for placing a busy guard condition upon the selected lines until after the transmission has been effected, and means for restoring said elements to normal in response to an end-of-message signal appended to the message transmitted to the selected lines. t

13. A selective telegraph transmission system comprising a main switching ofiice, a plurality of branch offices, lines connecting said branch offices to said main switching ofiice, a plurality of message transmitting devices at said main switchingoifice, a first selectivemeans for connecting one at a time said message transmitting devices-to selected individual ones of said lines over which messages are to be transmitted, a second. selective means for selecting a, plurality of desired lines over which a single message from one ofwsaid message transmitting devices is to be. transmitted simultaneously and for seizing the selected ones of said line as they become idle, means .to initiate simultaneous transmission from one of said message transmitting devices to all ofsaid desired lines after all have become idle and means to prevent the connecting of other of said messagetransmitting devices to said seized lines until after the simultaneous transmission of a message over the seized lines.

- 14. ,A multiple selective telegraph transmission system comprising a main switching oifice or exchange, a plurality of branch oflices r stations, lines connecting said branch ofiices or stations to said main switching ofiice, messagetransmitting equipment at said main switching oiiice, selective switching means for connecting said transmitting equipment to selected lines over which messages are, to .be transmitted, other selective means for designating two or more of said lines over whicha single broadcast message is to be transmitted simultaneously and for connecting said pluralityoi lines simultaneously to said trans- Knitting equipment, means to seize each of the desiredv lines asvthey become idle and auxiliary transmittingmeans associated with each line for transmitting characteristic supervisory code signal groups thereover, means to initiate the transmission of said supervisory code signal groups from said auxiliary transmitting means after all the desired lines have, been seized and means operative thereafter ,for transmitting the broadcast message to the seized lines.

15. A multiple selective telegraph transmission system comprising a main switching ofilce or exchange, a plurality of branch-offices or stations, lines connecting said branch oflices or stations to said main switching office, message repeating equipment at said main switching ofiice, selective switching, means for connecting said repeating equipment to selected lines over which messages are to be transmitted, operable means at said main switching office for selecting a plura ity f. lineslqver which a single message is to be transmittedconcurrently from said repeating equipment, means to initiate the operation of said repeating equipment when all of the lines ofa selected group become idle, means to automatically restore to normal the said means-forselecting a plurality of lines over which a single message is to be transmitted concurrentlyatthe end of the message and manually operable meansto restore said line selecting means to normal at any time prior to the operation. of said automatically restoring means. I

16. A selective telegraph system for sending messages over selected lines comprising a, transmitter, a manual switchboard including a con necting plug for extending the circuit ofsaid transmitter, and jacks forming terminals of said lines, said switchboard also containing a multisend jack, means for designating lines over, which it is desired to transmit a single message, means,

operative on the insertion of said connecting plug in said multisend jack to permit transmission from said transmitter simultaneously over the plurality of desiredones of said lines, seizing means associated with said multisend jack for seizing desired ones of said lines as they become idle, and a single manually operable switch for disabling, prior to the transmissionover the selected lines, said seizing means to release the seized ones of said lines and prevent further operation thereof.

17. A selective telegraph system for sending messages over selected lines comprising a transmitter, a manual switchboard including a connecting plug for extending the circuit of said transmitter, and jacks forming terminals of said lines, said switchboard also containing a multisend jack, means for designating groups of lines over which it is desired to transmit a message, means operative on the insertion of said connecting plug in said multisend jack to permit transmission from said transmitter simultaneously over the desired group of said lines, means associated with said multisend jack for seizing de-- sired ones of said lines as they become idle, means operative for releasing the seized ones of said lines if any are seized and to prevent the seizure of other lines of the selected group whereby the designated lines composing a group to be seized may be changed.

' GEORGE G. LIGHT.

Disclaimer 2,346,173.--George G. Light, Kew Gardens, N. Y. TRANSMISSION SYSTEM. Patent dated Apr. 11, 1944. Disclaimer filed Mar. 11, 1948, by the assignee, The

Western Union Telegraph Company. Hereby enters this disclaimer to claims 1, 2, 3, 4, 5, 7, 11, 13, and 15 of said patent.

[Oflicial Gazette April 13, 1948.] 

